By Brad Plumer
Huge winter storms have plunged large parts of the central and southern United States into an energy crisis this week as frigid blasts of Arctic weather crippled electric grids and left millions of Americans without power amid dangerously cold temperatures.
The grid failures were most severe in Texas, where more than four million people woke up Tuesday morning facing power failures.
Analysts have begun to identify a few key factors behind the grid failures in Texas. Record-breaking cold weather spurred residents to crank up their electric heaters and pushed demand for electricity beyond the worst-case scenarios that grid operators had planned for. At the same time, many of the state’s gas-fired power plants were knocked offline amid icy conditions, and some plants appeared to suffer fuel shortages as natural gas demand spiked nationwide. Many of Texas’ wind turbines also froze and stopped working, although this was a smaller part of the problem.
The resulting electricity shortfalls forced grid operators in Texas to impose rotating blackouts on homes and businesses, starting Monday, to avert a broader collapse of the system. Separate regional grids in the Southwest and Midwest are also coming under serious strain this week.
The crisis highlighted a deeper warning for power systems throughout the country. Electric grids can be engineered to handle a wide range of severe conditions — as long as grid operators can reliably predict the dangers ahead. But as climate change accelerates, many electric grids will face novel and extreme weather events that go beyond the historical conditions those grids were designed for, putting the systems at risk of catastrophic failure.
Building electric grids that are resilient in the face of increasingly wild and unpredictable weather will be an enormous challenge, experts said. In many cases, it may prove expensive, although, as Texas shows, the costs of grid failure can be extremely costly, too.
“It’s essentially a question of how much insurance you want to buy,” said Jesse Jenkins, an energy systems engineer at Princeton University. “What makes this problem even harder is that we’re now in a world where, especially with climate change, the past is no longer a good guide to the future. We have to get much better at preparing for the unexpected.”
A Grid Pushed to the Limit
Texas’s main electric grid, which largely operates independently from the rest of the country, is primarily designed to handle the state’s most predictable weather extremes: soaring summer temperatures that spur millions of Texans to turn up their air-conditioners all at once.
While freezing weather is rarer, grid operators in Texas have long known that electricity demand can also spike in the winter, particularly after severe cold snaps in 2011 and 2018 led millions of Texans to turn up their electric heaters and strained the system.
But this week’s winter storms, which buried the state in snow and ice, and led to record-cold temperatures, surpassed all expectations — and pushed the grid to its breaking point.
Texas’ grid operators had anticipated that, in the worst case, the state might need 67 gigawatts of electricity to handle a winter peak. But by Sunday evening, power demand had surged past 69 gigawatts. As temperatures dropped, many homes were relying on older, inefficient electric resistance heaters, which consume more power.
The problems compounded from there, as frigid weather knocked out of service power plants with more than 30 gigawatts of capacity by Monday night. The vast majority of those failures occurred at thermal plants, like natural gas generators, as plummeting temperatures paralyzed plant operations and soaring demand for natural gas nationwide appeared to leave some plants struggling to procure fuel. A number of the state’s power plants were also offline for scheduled maintenance in preparation for the summer peak.
At times, the state’s fleet of wind farms also lost up to 5 gigawatts of capacity, as many turbines froze in the icy conditions and stopped working.
“No one’s model of the power system envisioned that all 254 Texas counties would come under a winter storm warning at the same time,” said Joshua Rhodes, an expert on the state’s electric grid at the University of Texas, Austin. “It’s putting major strain on both the electricity grid and the gas grid that feeds both electricity and heat.”
Building In More Resilience
In theory, experts said, there are technical solutions that can avert such problems. But they can be costly to install, and the difficulty is in anticipating exactly when and where such solutions will be needed.
Wind turbines, for instance, can be equipped with heaters and other devices so that they can operate in icy conditions — as is often done in the upper Midwest, where cold weather is more frequent. Gas plants can be built to store oil on-site and burn the fuel if needed, as is often done in the Northeast, where natural gas shortages are more common. Grid regulators can design markets that pay extra to keep a fleet of backup power plants in reserve in case of emergencies, as is often done in the Mid-Atlantic.
But all of these solutions cost money, and grid operators are often wary of forcing consumers to pay extra for safeguards if they don’t think they will be needed.
“Building in resilience often comes at a cost, and there’s a risk of both underpaying but also of overpaying,” said Daniel Cohan, an associate professor of civil and environmental engineering at Rice University. “It’s a difficult balancing act.”
In the months ahead, as Texas grid operators and policymakers study this week’s winter storm, they may start to ask how and whether the grid might be bolstered to handle extremely cold temperatures. Is there aging infrastructure in dire need of repair? Would it make sense to build more connections between Texas’ power grid and other parts of the country to balance out electricity supplies — a move the state has long resisted? Should homeowners be encouraged to install costly backup battery storage units or more efficient heat pumps that use less electricity? Should the state’s electricity markets be tweaked to keep additional power plants in reserve?
One difficulty is that climate change is making it harder to prepare. Overall, the state is getting warmer as global temperatures rise, and cold-weather extremes are, on average, becoming less common over time.
But some climate scientists have also suggested that global warming could, paradoxically, bring more winter storms like the one seen this week. There is some research suggesting that Arctic warming is weakening the jet stream, the high-level air current that circles the northern latitudes and usually holds back the frigid polar vortex. This allows the cold air to escape to the South, especially when a blast of additional warming strikes the stratosphere and deforms the vortex. The result can be episodes of plunging temperatures, even in places that rarely get nipped by frost.
But this remains an active area of debate among climate scientists, with some experts less certain that polar vortex disruptions are becoming more frequent, making it even trickier for grid planners to anticipate the dangers ahead.
All over the country, electric utilities and grid operators are confronting similar questions, as climate change threatens to intensify heat waves, droughts, floods, water shortages and other calamities, all of which could create new and unforeseen risks for the nation’s electricity systems. Dealing with those risks will carry a hefty price tag: One recent study found that the Southeast alone may need 35 percent more electric capacity by 2050 simply to deal with the known hazards of climate change.
And the task of building resilience is becoming increasingly urgent. Many policymakers are increasingly promoting electric cars and electric heating as a way of curbing greenhouse gas emissions. But as more of the nation’s economy depends on reliable flows of electricity, the cost of failures will become ever more dire.
“This is going to be a significant challenge,” said Emily Grubert, an expert in electricity systems at Georgia Tech. “We need to decarbonize our power systems so that climate change doesn’t keep getting worse, but we also need to adapt to changing conditions at the same time. And the latter alone is going to be very costly. We can already see that the systems we have today aren’t handling this very well.”
John Schwartz contributed reporting.
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